Cleansing
by Lord of Kavaka
Summary: "You have both been exposed to a deadly pathogen," came a shaky voice, almost frantic. "And you have very little time. You need to strip and shower… NOW!" Season 4 AU. Rated M. Tumblr Prompt Fill. ONESHOT for CastleFanficMonday.


_*A/N: takes place some time after 'Cuffed'._

* * *

 **Cleansing**

* * *

A Season 4 Story

* * *

It was all a daze, a confusing blur of colors and sounds. One second they were stepping into a lab at Central Biogenetics with the intention of interviewing one of the head laboratory technicians, and then, before they knew it, alarm klaxons were blaring and men in yellow hazmat suits were grabbing them and directing them into a state of the art decontamination chamber with no windows and a big fan embedded in the ceiling above their heads.

"Kate… what… what the hell just happened?" Castle gasped, his hand clutching his heaving chest, his eyes wide with fright.

"I… I don't know, Castle," she said, trying to put on a brave front for him. She placed a hand on his shoulder in an attempt to reassure him. "Take deep breaths." He nodded. Her touch and words seemed to calm him. After a few minutes, her partner was visibly calmer, his breathing more regulated. Meanwhile, her heart was pulsating like a jackhammer inside her chest, memories of the last time men in hazmat uniforms rushed them into isolation were flooding her mind. But that was over a year ago. And things were different. Much… much different.

Beckett did a quick assessment of the room. It was small, had no windows—as previously noted, and there was a showerhead hanging off the wall in one of the corners, opposite several hangers holding white towels and gray utilitarian t-shirts, sweats pants, and undergarments of various sizes. Along the wall to her right was a handle that opened a disposal chute. She flicked her eyes around the entire room, and located a speaker box just above the door when a piercing squawk emitted from it.

" _You have both been exposed to a deadly pathogen,_ " came a shaky voice, almost frantic. " _And you have very little time. You need to strip and shower… NOW!_ "

She shook her head, even though the man obviously couldn't see her. She stepped over to the small electronic panel near the door and pressed the intercom button to respond. "No… that… we can't… um… in the same room?" Beckett protested falteringly. She swallowed thickly and cautiously glanced in Castle's direction. He was staring back at her with wide, panicked eyes.

" _No time!_ " came the voice again. " _Strip and shower. Now!_ "

"Strip?" hooted Castle in surprise, his eyes turning towards hers.

"That's what he said," Beckett sighed, feeling her face flush, whether from embarrassment or arousal at the idea of being naked and alone in a room with Castle was up for debate. She watched him gulp and spin around to face the speaker box.

"What? You can't be ser—?" His question dropped mid-word when he noticed Beckett shrug her coat off, and reluctantly toss it down the chute. It was a good coat, one of her favorites. She was going to miss it. "Whoa… Beckett, what are you doing?"

She gritted her teeth, and roughly yanked at the top buttons of her blouse. "You heard him, Castle," she said, trying to remain calm. "We've been exposed to a deadly pathogen. And I don't know about you, but I'm willing to suffer a little embarrassment if it means we get to live." She paused, and gave him a little glare. "Just… um… no looking, okay?"

Castle gaped at her for a long moment, and she licked her lips nervously as she finished unbuttoning her blouse. She held it closed self-consciously, and turned her back to him, shrugging it off and tossing it down the chute along with her stylish high heeled boots, which she parted with after great reluctance and a muffled curse. Ducking her head down, she closed her eyes and took deep breaths as she worked on unbuckling her belt, suddenly, almost irrationally embarrassed by her utilitarian underwear.

 _Get a grip, Kate_ , she muttered quietly to herself. _It's not like you woke up this morning knowing you'd be striping for Castle_.

Behind her, Beckett could hear Castle hurriedly following suit and divesting himself of his clothing. She could hear him grumbling about having to waste such a fine shirt. It made her smile, in spite of the dire situation. Keeping her back to him, Kate slowly removed her bra and then hesitated before pulling her matching black underwear down her long legs, throwing them down the chute with the rest of her clothing.

Holding one arm across her chest, while using her other hand to cover her center, she turned around and nearly lost her breath at the sight of Castle in all his naked glory. The man had no shame, not even bothering to shield his nakedness from her eyes. And of course the smug bastard noticed her wandering gaze, smirking and waggling his eyebrows at her in a highly suggestive manner. His present attitude was in stark contrast to his earlier surprised and baffled response to the orders from the man on the other end of the speaker box.

"Like what you see, Beckett?"

Beckett rolled her eyes, annoyed, trying to hide the fact that she did, in fact, like what she was seeing. She growled and narrowed her eyes at him in the fiercest glare she could muster. "Oh, grow up, Castle."

"Hey, I wasn't the one who said not to look!" he tossed back. "Though having said that, fell free to look as much as you want, Beckett."

He chuckled and turned around, stepping over to the shower stall, giving her the perfect view of his delicious backside. She swallowed and licked her lips, unable to prevent the overwhelming rise of arousal as it coursed through her veins, making her heart pump wildly with carnal want. It had been so long, and she'd spent the majority of her time since her recovery aching to feel Castle's touch, to feel the physicality of his love for her.

Meanwhile, Castle had managed to get the shower on and was in the process of rubbing soap into his hair. He cocked his head over his shoulder, and looked back at her. It startled her when she noticed his eyes remained on her face. Despite the circumstances, and his innuendo filled humor, Castle was being a true gentleman, even though she knew it was probably one of the greatest struggles of his entire life.

"Kate?"

"Coming," she said, and then cringed at the double meaning. She could feel her cheeks flush warm from the humiliation of it all.

Castle let out a low chuckle, and flashed her an appreciative wink, before turning his back to her and providing her with some privacy. Bless him. He really was such a sweet man. Oh… how she loved him. Heaving in a deep breath, Beckett padded over to join Castle in the corner. He stepped aside a little, giving her room to move under the hot spray of water. She closed her eyes, and let the water cascade down her head and back, soaking her hair. She slowly pirouetted in place, until she was completely wet.

The only problem was the shower wasn't the only reason why she was wet.

Squeezing her legs together in a futile attempt to stifle her arousal, Beckett reached for the second tube of disinfectant soap in the cradle embedded into the wall, and squirted a large dollop into her palm. After risking a glance at Castle, she reluctantly let her arm drop down from shielding her chest, and then lathered the soapy suds all over her body. Beckett was just about getting over the mortification this entire situation caused, when Castle's voice startled her.

"Can you do my back?" he asked in a soft, hesitant voice.

Blinking, she glanced up at him, and caught his expectant gaze.

"Um… yeah, sure," she stammered, flushing at the ridiculously of it all, stretching over for the tube to squirt another dollop of disinfectant soap into her hand while Castle respectfully turned his back to her.

Breathing deeply through her nose, Kate stared at the defined planes of Castle's bare back. She bit her lower lip… hard, trying to stifle the rising tide of lust as she tentatively reached forward and touched his bare flesh. She smoothed her hands across his broad shoulders, ignoring the slight groan that escaped his lips as she worked the soap into his skin. She tried to look straight ahead, stare at the back of his neck, but she couldn't prevent her eyes from dropping down to glimpse the delicious curve of his ass.

She groaned inwardly, cursing the universe for tempting her so.

And then, before she could protest, Castle was turning around, saying something about returning the favor. But she hadn't had time to move her gaze upwards. And now she was staring at his…

The speaker above the door squawked noisily, and a somewhat embarrassed and apologetic voice announced that it had been a false alarm, and that there hadn't really been any leak of a deadly pathogen. When the speaker went quiet, Beckett and Castle merely stood there in an awkward silence, frozen in place, her eyes still locked on his painfully obvious arousal. The only sound was the hum of the shower and the buzz from the large fan above their heads.

Castle snapped back to reality first. He shifted, turning away from her. When he spoke, his voice was a little higher than normal. "I… um… guess we can get off now… ah… I mean, dry off and… um… get dressed?"

Beckett swallowed thickly, her mind going a mile a minute as she processed everything she was feeling at that moment. She forced her eyes up to look at him, seeing how he was finally self-conscious, desperately working to cover his aroused state from her eyes. His cheeks were a bright red, and he kept his gaze averted. Her own modesty was forgotten with a sudden rush of relief at not having been exposed to a deadly disease. Her heart yearned to celebrate another lucky escape. And before she could stop or second-guess herself, Beckett grabbed his face in shaky hands, and pushed up on her toes to ram her mouth against his.

Castle stumbled back, startled, but soon responded in kind, slinking his arms around her slender waist and pulling her flush against him, deepening the kiss. Beckett let out a shaky moan, feeling her body quiver delightfully from the sensation of him so close and his erection pressing firmly against her flat stomach. Pulling back, she glanced up into his face, searching, for what, she did not know. But whatever it was she was looking for, she found it.

"Kate?" Castle questioned uncertainly as she grabbed his hand and tugged him back under the hot spray of water.

"Shh," she shushed him, putting a finger to his lips and smiling seductively. "How long has it been?"

"Uh?"

"Just… answer me, Castle."

"Okay," he replied hesitantly, swallowing. She hungrily watched the bob of his throat. "Since… um… since Gina and I broke up."

"Too long," she asserted, letting a hand trail down his stomach, taking great delight in the way his abdomen muscles clenched in response to her touch.

"Kate…?" he all but whined, so confused and baffled. "What… what are you doing?"

Beckett licked her lips and gazed down at the impressive sight. She'd always thought he'd just been cocky, that it was all hype and bravado, but it wasn't. Castle was quite the specimen. She recalled the quip she'd made about him and Sorenson needing to drop their pants for a measuring contest. Well, Castle would have definitely won.

"Kate?" he questioned again, his voice wavering with confusion and barely restrained want.

She dragged her eyes up, and finally looked at him, noticing his tortured expression. Moving her hand back up, she rested her palm over his heart, relishing the steady rhythm she found there.

"Do you want me?" she asked after a long beat.

He stared at her like she was crazy.

"Castle? Do you want me?" she asked again, more slowly this time.

He pursed his lips and swallowed, before answering. "Yes. Oh God, Kate… so… so very much."

Pushing aside any doubts she had in her mind about what she was about to do, knowing she wasn't entirely ready, but faced with him now, unable to resist her own desires, Beckett pushed up on her toes and kissed him again, solid and firm, leaving no room for any misunderstandings. His hands grabbed her hips and tugged her close. She groaned and nipped at his chin and jawline, smothering tiny kisses up to his ear.

"Then have me," she granted in a husky voice.

Growling low in his throat, Castle dropped his large hands to her ass, and squeezed. Beckett moaned approvingly and bucked her hips into him. He grabbed her thighs and hoisted her up, grunting from the strain.

"Take it easy, tiger," she soothed worriedly, and he struggled to move them towards the wall. She let out a groan as her back hit the wall. "Ugh, Castle!?"

"Sorry, sorry," he apologized, loosening his hold on her so she could put her feet back down on the solid ground.

"No," she shook her head, wrapping her arms around his neck as she listed into him. "Never apologize for loving me."

"What…," Castle hooted, pushing her back and glancing down her with a stunned expression. "You… you know?"

A long silence stood between them.

"Yes," she confessed, dipping her head down in shame. "I remember. I always have. I… Oh God, I'm sorry, Castle, so very sorry I never told you. I… I just needed time… to… fix myself, to get better. For me. For you. For… us."

"Kate, Kate, Kate," he chanted her name like a prayer, shaking his head. "You don't have to 'fix' yourself. I love you for you. I would never ask you to change. I love you, Kate… all of you. For everything you are."

"Really?" she gasped out, almost not believing what she was hearing, even though he'd spent the better part of a year proving just that.

"Really," he said, smiling back.

She laughed, suddenly feeling an invisible burden lift off her chest, cleansed of all her secrets. "Oh, Castle… Rick," she switched to his first name. This was important. She wanted him to know she was serious, and she only ever used his first name when things were of great import. "I love you, too. So… so very much. With all my heart."

His grinned widened, and before she could say anymore, he was on her, kissing her with an almost desperate intensity. She closed her eyes and melted into his embrace, reciprocating the passion. All too soon, he was puling away and meeting her questioning gaze with dark cobalt eyes.

"I'm still mad that you lied," he asserted in a quick breath. "But that discussion can wait for later."

"Yes," she nodded, willing to face that talk if it meant they had a chance at so much more. "Later."

With that agreed upon, Beckett pounced Castle and kissed him hard. He opened for her and she explored his mouth with her tongue, moaning at the taste of him. He tasted the same as he had that night long ago from a kiss they never talked about. She let her hands wander along his naked torso, before dropping below his waist and grabbing him firmly in her hand.

"They'll start wondering what's taking us so long, and I really don't want our first time to be… here," she explained breathlessly. "But, I can at least take care of this."

Castle groaned as she squeezed her fingers around him and began to pump her fist up and down his length. She bit her lower lip and glanced down, relishing the sight of her slim fingers wrapped around him. She flicked her thumb across his tip and he gasped, jerking his hips forward into her grasp. Beckett grinned victoriously, and tilted her head back up to steal more kisses from his lips as she quickened her strokes.

"Later… you'll have me… all of me, anyway you want," she murmured into his ear, making promises she knew were just as much for her as for him.

She rolled her wrist expertly and pumped harder and faster, feeling him tense in preparation. With one final twist of her fist, he let out a whimpering groan and a hot rope of white fluid shot out against her hand and stomach. She matched his groan, using her free hand to smear his release against her skin, before pulling her fingers up to her mouth and licking them clear. Castle let out a whimper at the sight, and Beckett flirted her eyes up to his, smirking saucily.

Before she could tease him any further, Castle surged forward, assaulting her mouth with his. She moaned approvingly, reveling in the passion and intensity of his embrace. He kissed her roughly, claiming her, his hands roaming all over her exposed skin, touching places she knew he'd longed to touch. So wrapped up in his explorations, Beckett didn't even register it before his lips found the scar between her breasts.

"Castle?" she asked, somewhat self-consciously, unable to hide the anxious tone of her voice.

He kissed the marred skin with reverence, and glanced back up at her, his hands gently stroking her sides. "You're beautiful, Kate," he assured her, seeing the self-doubt in her eyes. "So strong. So… extraordinary."

Beckett believed his every word. She nearly sobbed at the sincerity in his voice, the truth of his convictions. She could see the love and admiration her held for her reflecting out of his piercing blue eyes. Taking one of his hands in hers, she moved it up between her breasts, pressing it to her scar, willing him to feel the thump of her heart beneath.

"For you," she murmured over the din of the shower. "It beats only for you."

And then he was kissing her again. His large hand moved over to palm her breast, his thumb teasing her nipple, while his other hand slipped between her thighs and cupped her weeping core. He groaned as he felt her arousal, her need for him, and Beckett ground down into his hand, begging for some of that delicious friction.

Castle growled and sealed his mouth with hers as he complied with her wishes, stroking his fingers through her folds and flicking his thumb over her sensitive bundle of nerves. Her mouth dropped and she gasped in surprise as he inserted one finger inside her. And then another. He worked her good, bringing her to the heights of pleasure and beyond.

She grabbed his shoulders for support, burying her head in the crook of his neck to muffle her moans of euphoria. No man had ever pushed her over the edge so quickly. But then again, no other man had been him. Her Castle—the man who was quite possibly the love of her life.

Their sinfully delightful moment was shattered by the squawk of the speaker box, a man's worried voice inquiring what was taking them so long.

Ignoring him, Castle held her gently, lovingly, tenderly kissing her neck and jaw. Her eyelids fluttered open lazily as she gazed down between them, watching with hypnotic concentration as he slowly worked her down from her release. The feeling of his hands on her most intimate of areas was beyond anything she could have ever imagined. She bit her lower lip, and glanced up at him with a mischievous glint in her eyes.

"We should get dressed," she said.

"Do we have to?" he pouted, his eyes gazing down hungrily at her nakedness.

"I'm afraid so," she apologized, soothingly rubbing her hand down his side, feeling more confident and self-assured than she ever had when it came to him. "But, after we get cleared, we can go back to my place and continue."

Castle grinned at her, approving of the idea, and she smiled in return, loving the feeling that she no longer had to hide how she felt for this man. And then, because she now could, Kate Beckett kissed Richard Castle, soundly and with no reserve, making a promise for much more to come.

* * *

 _prompt from an **anon** on tumblr: During season 4, during a case, Caskett get caught up in some biohazard. They're quickly put into a decontamination chamber, and told to strip and shower. Castle cannot control becoming arousal next to a naked Beckett. Kate notices, of course, but doesn't comment. Halfway through the shower, the intercom buzzes to tell them it was a mistake, they weren't exposed to anything. Taking the opportunity, Beckett jerks him off and he returns the favor._


End file.
